JP6260083B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device in which a rotating electrical machine is disposed on the input side of a transmission mechanism.

  In recent years, for example, as represented by a vehicle such as a hybrid vehicle or an electric vehicle, a rotating electric machine is provided as a drive source, and the rotating electric machine is regenerated to convert kinetic energy of the vehicle into electric energy and collect it. Vehicles with improved energy efficiency are being actively developed.

  Conventionally, in order to obtain a sufficient amount of regeneration by the rotating electrical machine, for example, Patent Document 1 discloses a stepped vehicle in a hybrid vehicle in which a rotating electrical machine (motor generator) is disposed between an engine and a stepped automatic transmission. It describes that a rotary electric machine is regenerated at a high rotational speed by jumping and downshifting the automatic transmission.

  Further, Patent Document 2 describes that a frictional engagement element on the disengagement side is slip-engaged during power-off shifting and regeneration is performed by a rotating electrical machine.

JP 2008-94253 A JP 2011-213252 A

  By the way, the hybrid vehicle described in Patent Document 1 prohibits regeneration by the rotating electrical machine during the shift of the jump downshift and secures the deceleration during the shift by the friction brake. Therefore, there is a problem that the kinetic energy during the shift cannot be recovered and the energy efficiency is lowered.

  On the other hand, in order to solve the above problem, it is also conceivable to perform a shift while performing regeneration by slip-engaging a friction engagement element related to a shift as in the hybrid vehicle described in Patent Document 2. However, in this case, since the friction engagement element on the engagement side is responsible for the rotational braking force during the inertia phase, heat generation during slip engagement increases. In particular, in the case of a jump shift, the rotational speed difference of the input shaft of the automatic transmission is large before and after the shift, and the shift time is longer than that of a normal downshift shift. There was a problem that the amount became large.

  In addition to downshift gearshifts, upshift gearshifts, for example, when the accelerator is turned off after the accelerator is depressed and the brake is depressed, there is a state where it is desired to perform the jump upshift while securing the braking force. . Also in this case, from the viewpoint of energy efficiency, it is desired to exert braking force on the vehicle by regeneration of the rotating electrical machine while regenerating the rotating electrical machine as in Patent Document 2. However, as described above, the jump shift has a problem that the time required for the shift is long, and the amount of heat generated in the disengagement friction engagement element that takes charge of the rotational braking force also increases during the inertia phase.

  Therefore, the present invention improves the energy efficiency of the vehicle by performing regeneration of the rotating electrical machine without causing the friction engagement elements to generate more heat than necessary, and improves the drivability of the vehicle by reducing the number of shifts. An object of the present invention is to provide a vehicular control device.

The vehicle control device according to the present invention is configured to change the speed of the rotating electrical machine when shifting the speed change mechanism (6) in a regenerative state in which the rotating electrical machine (3) provided on the input side of the speed change mechanism (6) is regenerated. The friction engagement elements (C-1 to C-3, B-1, B-2, F) of the speed change mechanism (6) are maintained while maintaining the state where the regenerative braking force of (3) can be transmitted to the wheels (4). -1) a vehicle control device (10, 10A, 10B) for controlling the speed change mechanism (6) so as to perform the re-holding;
When performing the shift of the transmission mechanism (6) in the regenerative state, the target shift stage is determined, and when the shift from the current shift stage to the target shift stage is executed, the regenerative braking force is applied while performing slip rotation. The temperature of the main frictional engagement element to be transmitted (for example, C1 in the case of 6-1 shift and C1 in the case of 1-6 shift) is higher than the allowable temperature set in accordance with each friction engagement element. Determine whether or not
When it is determined that the temperature of the main body side frictional engagement element is equal to or lower than the allowable temperature, the speed change mechanism (6) is controlled to execute the speed change as it is,
When it is determined that the temperature of the main body side frictional engagement element is higher than the allowable temperature, the main body side during the slip rotation is performed so that the temperature of the main body side frictional engagement element is equal to or lower than the allowable temperature. The torque capacity (TR, TE) of the friction engagement element is set and the speed is changed while regenerating by the rotating electrical machine, and the fluctuation of the output torque (T _out ) transmitted to the wheel during the slip rotation is reduced. Thus, the brake device (8) of the wheel (4) is operated.
If it is determined that the temperature of the main frictional engagement element is higher than the allowable temperature, the brake device for the wheel (4) is based on the torque capacity of the main frictional engagement element during the slip rotation. The shared torque capacity of (8) is set, and the brake device (8) of the wheel (4) is operated based on the shared torque capacity.
In addition, the vehicle according to the present invention is
It has a plurality of friction engagement elements (C-1 to C-3, B-1, B-2, F-1), and the plurality of friction engagement elements (C-1 to C-3, B-1) , B-2, F-1), and a speed change mechanism (6) that forms a plurality of shift speeds,
A rotating electrical machine (3) provided on the input side of the transmission mechanism (6);
A brake device (8) provided on the wheel (4);
When shifting the speed change mechanism (6) in a regenerative state in which the rotating electrical machine (3) is regenerated, the speed change is performed while maintaining a state where the regenerative braking force of the rotating electrical machine (3) can be transmitted to the wheels. A control unit (10) for controlling the speed change mechanism (6) so that the frictional engagement elements (C-1 to C-3, B-1, B-2, F-1) of the mechanism (6) are replaced. )
The control unit (10) is in the non-braking state at the start of the shift according to the differential rotation before and after the shift and / or the required shift time when performing the shift of the transmission mechanism (6) in the regenerative state. the torque capacity of the brake device (8) is varied during the shift to share the braking force in the shifting, and said at shift end you said brake device and a non-braking state, it is characterized.

  Further, by calculating the amount of heat generated in the main frictional engagement element at the time of shifting, and determining whether the amount of heat generation is greater than the heat generation amount limit value set according to each friction engagement element, It is preferable to determine whether or not the temperature of the main body side frictional engagement element is higher than the allowable temperature at the time of shifting.

Further, the current temperature of the main frictional engagement element is calculated based on the accumulated heat balance before the shift, and the amount of heat generated in the main frictional engagement element during the shift is calculated. Based on the current temperature of the frictional engagement element and the amount of heat generated in the main body side frictional engagement element at the time of shifting, an estimated temperature of the main body side frictional engagement element during shifting is obtained,
It is determined whether or not the temperature of the main frictional engagement element during shifting is greater than the allowable temperature based on whether or not the estimated temperature of the main frictional engagement element during the shift is greater than the allowable temperature. It is preferable.

  In the case where the target shift stage is a shift stage that is a plurality of stages away from the current shift stage and the shift is performed by changing one friction engagement element forming the current shift stage, this one friction engagement element It is preferable that a frictional engagement element (for example, C1 in the case of 6-2 shift) that transmits the regenerative braking force while performing slip rotation is used as the main-side frictional engagement element.

  Further, in the case where the target shift speed is a shift speed away from the current shift speed by a plurality of speeds and the two friction engagement elements forming the current shift speed are changed, these two friction engagement elements It is preferable that each friction engagement element (for example, C1 and C3 in the case of 6-3 shift) that transmits the regenerative braking force while slip-rotating is used as the main-side friction engagement element. .

  Further, it is preferable that the heat generation amount is calculated based on a required time required for shifting, a rotational speed difference of the shifting mechanism before and after shifting, and a torque capacity of the main frictional engagement element.

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

  According to the first aspect of the present invention, it is determined whether or not the temperature of the main-side frictional engagement element that transmits the regenerative braking force while performing the slip rotation becomes higher than the allowable temperature during the shift. When it is determined that the temperature of the main body side frictional engagement element is higher than the allowable temperature, the main body side frictional engagement element at the time of slip rotation is adjusted so that the temperature of the main body side frictional engagement element is equal to or lower than the allowable temperature. Set the torque capacity. By setting the torque capacity of the main frictional engagement element during slip rotation in accordance with the thermal limitation of the main frictional engagement element, the temperature of the main frictional engagement element becomes higher than the allowable temperature during gear shifting. Heating can be prevented. As a result, it is possible to freely set the target shift stage so as to minimize the number of shifts, and for example, even in a shift where a large amount of heat is generated in the main frictional engagement element during a shift such as a jump shift. The energy can be recovered by regeneration to increase the energy efficiency. Furthermore, during the slip rotation, a wheel brake device is used to reduce fluctuations in output torque, so even if the regenerative braking force transmitted to the wheel during the slip rotation decreases, the shock generated in the vehicle is reduced. In combination with the fact that the number of shifts can be reduced, an improvement in drivability can also be achieved.

  According to the invention according to claim 2, by calculating the amount of heat generated in the main frictional engagement element at the time of shifting, and comparing this heat generation amount and the heat generation amount limit value set for each friction engagement element, Whether or not the temperature of the main frictional engagement element becomes higher than the allowable temperature during a shift can be easily determined based on the amount of heat generated during one shift.

  According to the third aspect of the invention, in addition to the amount of heat generated in the main body side frictional engagement element at the time of shifting, the calculation of the current temperature of the main body side frictional engagement element is also performed based on the accumulated heat balance before shifting. Then, based on the heat generation amount and the current temperature, the estimated temperature of the main frictional engagement element during the shift is calculated. As described above, the estimated temperature of the main frictional engagement element during the shift is calculated in consideration of the current temperature of the main frictional engagement element when the shift is started, thereby more accurately determining the estimated temperature of the main frictional engagement element during the shift. It can be determined whether the frictional engagement element exceeds an allowable temperature.

  According to the fourth aspect of the present invention, in the case of a shift in which one frictional engagement element that currently forms the gear position is changed, when the one frictional engagement element is replaced, regeneration is performed while slipping. The frictional engagement element that transmits the braking force is referred to as a main frictional engagement element. For this reason, it is possible to reliably determine whether or not the temperature of the frictional engagement element that increases the amount of heat generated at the time of shifting is equal to or higher than the allowable temperature at the time of shifting.

  According to the fifth aspect of the present invention, in the case of a shift in which two friction engagement elements that currently form a gear stage are changed, slip rotation is performed when each of these two friction engagement elements is changed. However, each friction engagement element that transmits the regenerative braking force is referred to as a main-side friction engagement element. For this reason, it is possible to reliably determine whether or not the temperature of the frictional engagement element that increases the amount of heat generated at the time of shifting is equal to or higher than the allowable temperature at the time of shifting.

  According to the sixth aspect of the invention, the amount of heat generated by the main frictional engagement element is calculated using the required time required for the shift, the rotational speed difference of the transmission mechanism before and after the shift, and the torque capacity of the main frictional engagement element. can do.

1 is a schematic diagram showing a hybrid vehicle according to a first embodiment of the present invention. The skeleton figure which shows the hybrid drive device of the hybrid vehicle of FIG. The engagement table of the speed change mechanism of the hybrid drive device of FIG. FIG. 3 is a shift map of a transmission mechanism of the hybrid drive device of FIG. 2. It is a graph which shows the relationship between the torque of a main body side friction engagement element, and the rotational speed of an input shaft, Comprising: (a) is a case of regenerative downshift, (b) is a case of regenerative upshift. It is a graph which shows the relationship between the torque of a main body side frictional engagement element when the temperature of a main body side frictional engagement element is set to below an allowable temperature, and an output torque, Comprising: (a) is the case of regenerative downshift , (B) shows the case of regenerative upshift. 6A and 6B are graphs in the case where the regenerative braking force is supplemented by a wheel brake device, where FIG. 6A is a case of a regenerative downshift and FIG. 6B is a case of a regenerative upshift. (A) The figure which shows the calculation method of the post-restriction torque capacity | capacitance of the main body side frictional engagement element and the brake device share torque capacity | capacitance at the time of downshift speed change, (b) The post-restriction torque of the main body side frictional engagement element at the time of upshift speed change The figure which shows the calculation method of a capacity | capacitance and a brake device share torque capacity. The graph which showed transition of the presumed temperature of the main body side friction engagement element during driving | running | working of a vehicle. FIG. 6 is a graph for explaining a difference in estimated temperature of the main frictional engagement element due to a difference in current temperature of the main frictional engagement element at the start of the shift, wherein (a) is a regenerative downshift transmission; (b) For regenerative upshift. (A) The figure which shows the calculation method of the post-restriction torque capacity | capacitance of the main body side frictional engagement element and the brake device share torque capacity | capacitance at the time of the downshift according to the 2nd Embodiment of this invention, (b) The figure which shows the calculation method of the post-restriction torque capacity | capacitance of the main body side friction engagement element at the time of the upshift and the brake device share torque capacity | capacitance based on 2 embodiment.

  Hereinafter, a vehicle control device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the drive connection refers to a state in which the rotating elements are connected so that the driving force can be transmitted, and the rotating elements are connected so as to rotate integrally, or these rotating elements. Is used as a concept including a state in which driving force is transmitted through a clutch or the like. The jump shift is a shift that shifts to a shift stage that is separated from the current shift stage by a plurality of stages.

<First Embodiment>
<Schematic configuration of hybrid drive device>
As shown in FIGS. 1 and 2, a hybrid vehicle (hereinafter simply referred to as a vehicle) 1 has a rotating electrical machine (hereinafter referred to as a motor generator or simply a motor) 3 in addition to an internal combustion engine 2 as a drive source. Yes. A hybrid drive device 100 as a vehicle drive device that constitutes the power train of the vehicle 1 is a one-motor type hybrid drive device, and a speed change disposed on a transmission path between the internal combustion engine 2 and the wheels 4. It has a mechanism 6 and an input unit 5 between the transmission mechanism 6 and the internal combustion engine 2.

  As shown in FIG. 2, the speed change mechanism 6 has a plurality of friction engagement elements C-1 to C-3, B-1, B-2, and F-1, and replaces the plurality of friction engagement elements. The multi-stage automatic transmission (stepped automatic transmission) that achieves a plurality of shift speeds by changing the transmission path of the transmission gear mechanisms SP and PU.

  The input unit 5 includes a motor 3 and an engine connecting clutch K0. The engine connecting clutch K0 includes an engine connecting shaft 9 that is drivingly connected to a crankshaft of the engine 2 and a transmission mechanism 6. The power transmission to and from the input shaft 11 is connected and disconnected. Further, the motor 3 is disposed on the input side of the speed change mechanism 6 (on the side of the power transmission path, opposite to the side that is drivingly connected to the drive wheels 4), and is drivingly connected to the input shaft 11 of the speed change mechanism 6. ing.

  Therefore, when the hybrid drive device 100 drives both the internal combustion engine 2 and the motor 3 to drive the vehicle, the control unit (ECU, control device) 10 controls the hydraulic control device 12 to control the clutch K0. At the time of EV traveling that is engaged and travels only by the driving force of the motor 3 that is drivingly connected to the transmission path on the wheel side, the clutch K0 is released to separate the transmission path on the internal combustion engine 2 side from the transmission path on the wheel side. It is like that.

  Further, the control unit 10 includes an input shaft rotation speed sensor 13 that detects the rotation speed of the input shaft 11 of the transmission mechanism 6 that rotates in the same manner as the motor 3, and a vehicle speed sensor that detects the rotation speed of the output shaft 14 of the transmission mechanism 6. 15, sensors such as an accelerator opening sensor 16 and a brake sensor 17 are communicably connected. The control unit 10 controls the hydraulic pressure based on the accelerator opening detected by the accelerator opening sensor 16, the brake pedal depression amount detected by the brake sensor 17, and the rotational speed (vehicle speed) of the output shaft 14 detected by the vehicle speed sensor 15. The device 12 is controlled to engage / disengage the friction engagement elements C-1 to C-3, B-1, and B-2 of the transmission mechanism 6 to switch the gear position of the transmission mechanism 6. Moreover, the control part 10 can operate the brake device 8 provided in the wheel 4 according to the depression amount of the said brake pedal.

<Configuration of transmission mechanism>
Next, a specific configuration of the speed change mechanism 6 will be described. As shown in FIG. 2, the speed change mechanism 6 includes a planetary gear SP and a planetary gear unit PU on the input shaft 11. The planetary gear SP is a so-called single pinion planetary gear that includes a sun gear S1, a carrier CR1, and a ring gear R1, and has a pinion P1 that meshes with the sun gear S1 and the ring gear R1.

  The planetary gear unit PU has a sun gear S2, a sun gear S3, a carrier CR2, and a ring gear R2 as four rotating elements. The carrier CR2 has a long pinion PL that meshes with the sun gear S2 and the ring gear R2, and the sun gear S3. This is a so-called Ravigneaux type planetary gear that has meshing short pinions PS that mesh with each other.

  The sun gear S1 of the planetary gear SP is fixed to the transmission case 18, and the ring gear R1 is drivingly connected to the input shaft 11 so as to rotate the same as the input shaft 11 (hereinafter referred to as “input rotation”). "). Further, the carrier CR1 is decelerated by decelerating the input rotation by the fixed sun gear S1 and the ring gear R1 that rotates, and is connected to the clutch C-1 and the clutch C-3.

  The sun gear S2 of the planetary gear unit PU is connected to the brake B-1 so as to be freely fixed to the transmission case 18, and is connected to the clutch C-3 via the clutch C-3. The deceleration rotation of CR1 can be freely input. The sun gear S3 is connected to the clutch C-1, so that the decelerated rotation of the carrier CR1 can be input.

  Further, the carrier CR2 is connected to the clutch C-2 to which the rotation of the input shaft 11 is input, and the input rotation can be input via the clutch C-2. Connected to the brake B-2, the rotation in one direction is restricted with respect to the transmission case 18 via the one-way clutch F-1, and the rotation can be fixed via the brake B-2. . The ring gear R2 is connected to a counter gear, and the counter gear is connected to a wheel 4 (see FIG. 1) via a counter shaft and a differential device.

  In the transmission mechanism 6 having the above-described configuration, the clutches C-1 to C-3, the brakes B-1 and B-2, and the one-way clutch F-1 shown in the skeleton diagram of FIG. The first forward speed (1ST) to the sixth forward speed (6TH) and the first reverse speed (Rth) are achieved, and the rotation input to the input shaft 11 is changed at each speed stage. And output to the wheel 4.

<Background of shifting in the regenerative state>
By the way, in the hybrid drive device 100 on which the motor 3 described above is mounted, it is desired to improve the energy efficiency by regenerating the motor 3 as much as possible to convert the kinetic energy into electric energy and recover it. At this time, the motor 3 is desirably regenerated within the range of the rotational speed with the highest regeneration efficiency, and from the viewpoint of drivability, the motor 3 is desirably regenerated on the equal power line. Therefore, it is desirable that the regeneration of the motor 3 is executed in a high rotation range.

  On the other hand, the drag torque of the transmission mechanism 6 increases as the rotational speed of the input shaft 11 increases. For this reason, as shown in FIG. 4, in the shift map of the speed change mechanism 6 in which the motor 3 is disposed on the input side, when there is no regeneration request, the high gear stage is selected to reduce the rotation of the input shaft 11. When there is a regenerative request, the gear shift point is set so that the low gear stage is selected and the input shaft 11 is rotated at a high speed, and the target gear stage changes depending on the presence or absence of the regenerative request. ing.

  Therefore, when the brake pedal is stepped on and the regeneration request increases, the speed change mechanism 6 downshifts over a plurality of stages while regenerating the motor 3 in order to regenerate the motor 3 in an efficient rotational speed range. It may be necessary to shift gears (see arrow A in FIG. 4). On the upshift side, as shown by an arrow B in the figure, when there is a braking request when the accelerator is released from a state where the accelerator is depressed, a plurality of shifts are performed while regeneration is performed by the motor 3. In some cases, it is necessary to perform upshifts across the gears.

  Here, in both the regenerative downshift shift which is a downshift shift performed while regenerating the motor 3 and the regenerative upshift shift which is an upshift shift performed while the motor 3 is regenerating, the target shift stage after the shift. However, when there is a plurality of positions away from the current shift speed, there is a demand for shifting to the target shift speed with the smallest possible number of shifts in order to improve the regeneration efficiency and the drivability.

  For this reason, if the target gear stage after the shift is a plurality of stages away from the current gear stage, it is conceivable to execute a jump shift that performs a shift by skipping the shift stage without performing a shift step by step. In executing the jump shift, there are the following problems in the case of the shift in the regenerative state.

  That is, when shifting the speed change mechanism 6 in a regenerative state in which the motor (rotating electrical machine) 3 provided on the input side of the speed change mechanism 6 is regenerated, the braking force of the vehicle is secured by the regenerative force of the motor 3. For this reason, the control unit 10 controls the speed change mechanism 6 so as to change the friction engagement element while maintaining a state where the regenerative braking force of the motor 3 can be transmitted.

  Specifically, as shown in FIG. 5A, in the regenerative downshift, the torque capacity TE of the frictional engagement element on the engagement side is increased to a value T1 corresponding to the regenerative braking force in the inertia phase. Shifting. Further, as shown in FIG. 5B, in the regenerative upshift, in the inertia phase, the torque capacity TR of the disengagement side frictional engagement element is lowered within a range T2 in which regenerative braking loss is permitted, and the rotational speed change is reduced. Shifting while realizing.

  As described above, the speed change when the motor 3 is in the regenerative state is higher than that of a conventional vehicle drive device (vehicle drive device that does not have a motor) that generates a negative torque only for the engine friction torque at the maximum. Thus, the shift is performed under a high negative torque by the negative torque of the motor 3 due to regeneration. That is, in the case of the regenerative downshift, the torque capacity of the frictional engagement element on the engagement side in the inertia phase is higher than the conventional vehicle drive device by the negative torque of the motor 3. ing. Further, in the regenerative upshift, the disengagement side frictional engagement element has a disengagement side frictional engagement element in the inertia phase as compared with the conventional vehicle drive device in which the inertial phase does not have torque capacity. Has torque capacity equivalent to braking force.

  For this reason, the frictional engagement element that performs re-grip rotates in a slip state with a torque capacity corresponding to the regenerative braking force that can transmit the regenerative braking force to the wheels 4, and therefore occurs in the inertia phase. The amount of heat generated increases.

  In the jump shift, the difference in rotational speed before and after the shift of the input shaft 11 of the transmission mechanism 6 necessary for performing the shift is larger than that in a normal shift that shifts one step at a time. The required time for shifting becomes longer than that. Therefore, if the amount of heat generated to transmit the regenerative braking force increases even more and the inertia phase becomes longer by performing a jump shift, the friction engagement that transmits the regenerative braking force while performing slip rotation The amount of heat generated in the friction plate of the element (the engagement-side friction engagement element at the time of the downshift and the release-side friction engagement element at the time of the upshift, hereinafter referred to as the main-side friction engagement element). , The temperature may become higher than the allowable temperature of the friction engagement element. Note that the allowable temperature is a limit temperature set so that damage due to heat, such as seizure, does not occur in the frictional engagement element during the shift, and is set for each frictional engagement element.

On the other hand, if the torque transmitted by the main frictional engagement element during slip rotation is reduced so that the temperature of the main engagement element during the shift does not exceed the allowable temperature, for example, in the case of the regenerative downshift As shown in FIG. 6A, the torque capacity TR of the engagement side frictional engagement element in the inertia phase is larger than the torque capacity T1 required to transmit the regenerative braking force output at the start of the shift. There is a risk that it will become smaller (T1> TR). Then, the regenerative braking force desired to be output cannot be transmitted by the engagement-side frictional engagement element, and therefore only the torque T4 corresponding to the difference T3 between the torque capacity T1 and the torque capacity TR of the engagement-side frictional engagement element. The output torque T _out output to the wheel 4 in the inertia phase increases, and there is a risk that braking will be lost during the shift.

Also, as shown in FIG. 6B, in the case of the regenerative upshift, similarly, the torque of the disengagement side frictional engagement element in the inertia phase in order to keep the temperature of the main body side frictional engagement element below the allowable temperature. When the capacity TE is smaller than the torque capacity T1, an output torque output to the wheel 4 by a torque T6 corresponding to a difference T5 between the torque capacity T1 and the torque capacity TE of the disengagement side frictional engagement element in the inertia phase. There is a possibility that fluctuations occur in T _out and braking may be lost during a shift.

  Therefore, the control unit 10 according to the present embodiment reduces the number of shifts as much as possible and prevents a shift loss in the torque phase while preventing an excessive thermal load from being generated on the frictional engagement elements that perform the above-mentioned reshuffling. The speed change mechanism 6 and the brake device 8 of the wheel 4 (see FIG. 1) during the regenerative shift are controlled so as to improve the regenerative efficiency and drivability by reducing the speed.

In particular, the control unit 10 according to the present embodiment, as shown in FIG. 7, has a braking force (that is, the torque capacity of the torque capacity) that cannot be held due to thermal restriction of the main frictional engagement element. The difference T3, T5) is guaranteed by the wheel brake device 8 (sharing torques T7, T8 that the brake device 8 is responsible for). For this reason, for example, even in a shift where a large thermal load is generated in the main frictional engagement element such as the above-described jump shift, the output torque T is generated while the motor 3 is regenerated and the kinetic energy is recovered. _Out drivability is reduced to achieve good drivability. Hereinafter, the operation of the control unit 10 during the regenerative shift will be described in detail for the case of the regenerative downshift and the case of the regenerative upshift.

<Regenerative downshift>
When the regenerative downshift is determined based on the shift map, the control unit 10 determines the target shift stage so that the shift is performed in one shift to the determined shift stage. When the target shift speed is determined, as shown in FIG. 8, when performing the regenerative downshift, the control unit 10 determines the maximum torque and maximum power that the motor 3 can currently output, and the input shaft after the shift. 11, rotational speed of the motor, current motor torque, inertia generated in the rotating member on the input side of the engagement side frictional engagement element (main frictional engagement element) (connected to the drive system on the input side rather than the frictional engagement element) The maximum rotational change acceleration that can be generated by the motor 3 on the input shaft 11 of the speed change mechanism 6 is calculated based on the total inertia of the rotating elements).

  That is, the control unit 10 functions as a maximum rotation change acceleration calculation unit 30 that calculates the maximum rotation change acceleration, and calculates a motor torque that can be output by the motor 3 after the shift from the motor maximum power and the rotation speed after the shift. Further, the value of the maximum torque that can be output by the motor 3 is acquired by inverter control, and the smaller value of the motor torque calculated from the motor maximum power and the acquired motor maximum torque is set as the torque that can be output by the motor 3. .

  Then, the control unit 10 calculates the maximum inertia torque that can be output from the motor 3 from the torque that can be output from the motor 3 and the current motor torque, and uses the maximum inertia torque as the friction coefficient on the engagement side. By dividing by the inertia generated in the rotating member on the input side of the combined element, the maximum rotational change acceleration that the motor 3 can generate on the input shaft 11 of the speed change mechanism 6 is calculated.

  Further, since the rotational speed of the input shaft 11 before and after the shift is set in advance, the control unit 10 determines the rotational speed difference of the input shaft 11 necessary for performing each shift, that is, the speed change mechanism 6 before and after the shift. The rotational speed difference of the input shaft 11 can be obtained (differential rotation calculation unit 31). The control unit 10 functions as the desired shift time calculation unit 32, thereby dividing the rotational speed difference of the transmission mechanism 6 before and after the shift by the maximum rotation change acceleration and performing the desired shift required for the shift. Calculate the time (period of inertia phase).

  Further, the control unit 10 also functions as a pre-restricted torque capacity calculation unit 33, and an input torque to the speed change mechanism 6 from the engine friction torque (only when the engine is connected to the power transmission system) and the motor driving torque. Is calculated by multiplying the input torque to the transmission mechanism 6 by the sharing ratio of the frictional engagement element on the engagement side, thereby calculating the pre-limit torque capacity of the frictional engagement element on the engagement side.

  When the required time required for the shift, the rotational speed difference of the speed change mechanism before and after the shift, and the torque capacity before the limit of the frictional engagement element on the engagement side are obtained, the control unit 10 functions as the calorific value calculation unit 34. Based on the calculated shift required time, the difference in rotational speed of the input shaft 11 of the transmission mechanism before and after the shift, and the torque capacity of the friction engagement element on the engagement side, Side heat engagement element) is calculated.

  When the calorific value of the engagement-side frictional engagement element is calculated, the control unit 10 functions as the thermal load determination unit 37, and the calorific value that is calculated in accordance with each frictional engagement element is set by the calculated calorific value. Determine whether it is greater than the value. In other words, the control unit 10 determines whether or not the heat generation amount is larger than the heat generation amount limit value, so that when the shift from the current gear stage to the target gear stage is executed, the friction engagement on the engagement side is performed. It is determined whether or not the temperature of the element (main body side frictional engagement element) is higher than the allowable temperature described above. The heat generation amount limit value is an upper limit value of the heat generation amount allowed to be generated in the main frictional engagement element during one shift, and is set according to the allowable temperature of each friction engagement element. Yes.

  When the calculated heat generation amount is equal to or less than the heat generation amount limit value, the regenerative braking force at the start of the shift can be transmitted to the torque capacity TE of the engagement side frictional engagement element (main frictional engagement element) in the inertia phase. Even when the pre-restricted torque capacity (torque capacity T1 in FIG. 7), which is a value, is set, the temperature of the frictional engagement element on the engagement side does not exceed the allowable temperature. Therefore, in this case, the control unit 10 that functions as the post-restricted torque capacity calculation unit 38 uses the value of the pre-restriction torque capacity that does not take thermal restriction into the torque capacity of the friction engagement element on the engagement side after restriction as it is. To do. Further, in this case, since the braking force required during the shift can be output by the motor 3, the control unit 10 performs the torque capacity shared by the brake device 8 in the inertia phase (during gear shift) (hereinafter, the brake device shared torque capacity). Is set to 0. That is, when the calculated heat generation amount is equal to or less than the heat generation amount limit value, the control unit 10 controls the transmission mechanism 6 so as to execute the shift as it is.

  On the other hand, when the calculated heat generation amount is larger than the heat generation amount limit value, if the torque capacity of the engagement-side friction engagement element is the above-described pre-limit torque capacity (torque capacity T1), the friction on the engagement side during shifting There is a possibility that the temperature of the engaging element exceeds the allowable temperature. Therefore, the control unit 10 sets the post-limit torque capacity so that the temperature of the friction engagement element does not exceed the allowable temperature during the shift based on the heat generation amount limit value, the required shift time, and the rotational speed difference before and after the shift. calculate. Specifically, the control unit 10 calculates the post-restricted torque capacity so that the maximum value is obtained in a range where the temperature of the friction engagement element does not exceed the allowable temperature during the shift.

In this case, the control unit 10 also functions as the brake device shared torque capacity calculation unit 39, and sets the above-described brake device shared torque capacity based on the torque capacity before and after the limit and the clutch sharing ratio. That is, the control unit 10 limits the torque capacity before the limit and the limit so that the output torque _Tout does not fluctuate due to a lack of the regenerative braking force transmitted by the frictional engagement element on the engagement side in the inertia phase. A torque capacity corresponding to a difference from the rear torque capacity (T7 in FIG. 7A) is set as the value of the brake device-sharing torque capacity. Then, the control unit 10 sets the calculated post-restricted torque capacity and the brake device-sharing torque capacity as the engagement-side friction engagement element and the torque capacity of the brake device 8, respectively, and executes a shift. Yes.

  The control unit 10 uses the same method not only in the case of a jump shift where the target shift stage is a shift stage that is a plurality of stages away from the current shift stage, but also in the case where the shift stage before and after the shift is one stage. Change gears. Further, in the case of a shift in which the shift changes one gripping engagement element that currently forms the shift stage, the main frictional engagement element (for example, 6-2) at the time of changing the gripping of the one friction engagement element. In the case of shifting, the post-restricted torque capacity and the brake device shared torque capacity are calculated for C1).

  Further, the control unit 10 may change the two gears when the gear shift is a gear shift (for example, a 6-3 gear shift) that changes both of the two friction engagement elements that currently form the gear stage, such as a four-element shift gear shift. The post-restricted torque capacity and the brake device-sharing torque capacity are calculated for each of the main-side friction engagement elements (for example, C1 and C3 in the case of 6-3 shift) when each of the friction engagement elements is gripped.

<Regenerative upshift gear shift>
On the other hand, in the case of the regenerative upshift, as in the case of the regenerative downshift, when the determination of the regenerative upshift is made based on the shift map, one shift is performed up to the determined shift stage. A target shift stage is determined so as to shift.

  Then, as shown in FIG. 8B, the post-restricted torque capacity and the brake device-sharing torque capacity are calculated by the same method as in the case of the regenerative downshift, and the shift is executed. Since the regenerative upshift is an upshift, the maximum inertia torque that the motor 3 can output is calculated from the minimum torque and the minimum power of the motor. Specifically, since it is an upshift, the maximum inertia torque has a negative value, and the maximum rotation change acceleration also has a negative value. Further, the main-side frictional engagement element for which the post-restricted torque capacity is calculated is a release-side frictional engagement element instead of the engagement-side frictional engagement element.

  As described above, when the control unit 10 determines that the temperature of the main frictional engagement element is higher than the allowable temperature at the time of shifting, the controller 10 performs slip rotation so that the temperature of the main frictional engagement element is equal to or lower than the allowable temperature. The torque capacity of the main frictional engagement element at the time is set. By setting the torque capacity of the main body side frictional engagement element during slip rotation in accordance with the thermal limit of the main body side frictional engagement element, the temperature of the main body side frictional engagement element becomes equal to or higher than the allowable temperature during shifting. Can be prevented. For this reason, it is possible to freely set the target shift speed so as to minimize the number of shifts, and even in a shift where a large amount of heat is generated in the main frictional engagement element during a shift such as a jump shift. The energy can be recovered by regeneration.

  Furthermore, by reducing the number of shifts, energy loss during shifts can be reduced, and the rotating electrical machine can be regenerated within a range of efficient rotation speeds at an early time. Energy efficiency can be improved.

Further, when the slip rotation, using a braking device 8 of the wheel 4, to reduce the fluctuation of the output torque T _out, even as a regenerative braking force transmitted to the wheels becomes small when the slip rotation occurs vehicle Shock can be suppressed to a small extent, and in combination with the fact that the number of shifts can be reduced, an improvement in drivability can also be achieved.

<Second Embodiment>
Next, a vehicle control apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The second embodiment differs from the first embodiment in that the current temperature of the main frictional engagement element is taken into account when calculating the post-restricted torque capacity and the brake device shared torque capacity. It is different. Therefore, in the following description, only differences from the first embodiment will be described, and description of other parts will be omitted.

  FIG. 9 is a diagram showing a transition of the estimated temperature of the main frictional engagement element during traveling of the vehicle. In FIG. 9, the main body side frictional engagement element is gripped at time points t1 to t2 and time points t3 to t4, and heat is generated by the slip rotation while transmitting the regenerative braking force at the time of shifting, and the temperature rises. I understand that In addition, during the period from time t2 to t3 when the main frictional engagement element is not gripped, the temperature of the main frictional engagement element is decreased to the temperature of hydraulic oil (hereinafter referred to as ATF) in the transmission mechanism 6. It turns out that it is converging.

  Here, at the start time t1 of the first shift, the estimated temperature of the main frictional engagement element is substantially equal to the oil temperature of the ATF, but the first shift is performed as in FIG. When the second shift is performed at a relatively close interval, at the start time t2 of the second shift, the heat raised during the first shift remains. At the time t2 when the second shift is started, the estimated temperature of the main frictional engagement element is higher than the temperature at the time t1.

  Therefore, in the first and second shifts, even if the amount of heat generated in the main friction engagement element is equal, depending on the temperature of the main friction engagement element at the start of the shift, It is possible that the temperature of the main frictional engagement element is higher than the allowable temperature or lower than the allowable temperature.

  That is, as shown in FIG. 10, even if a completely similar shift is executed, if the temperature at the shift start time is high, the estimated temperatures X1 and X2 of the main frictional engagement elements exceed the allowable temperature, and the shift start point When the temperature is low, the estimated temperatures X3 and X4 of the main frictional engagement element may not exceed the allowable temperature.

  For this reason, in the present embodiment, the transmission mechanism and the brake device are controlled at the time of shifting in consideration of the current temperature of the main frictional engagement element. That is, as shown in FIG. 11, the control unit 10A according to the present embodiment functions as a current temperature calculation unit, and accumulates the heat balance before shifting (heat input and heat dissipation of the main frictional engagement element). The current temperature of the main body side frictional engagement element is always calculated and estimated based on the sum of the ATF and the oil temperature of the ATF.

  When the controller 10A calculates the heat generation amount of the main frictional engagement element at the time of shifting, it functions as an estimated temperature calculation unit 40, and the current temperature of the main frictional engagement element and the main frictional engagement element at the time of the shift are controlled. Based on the amount of heat generated, an estimated temperature of the main frictional engagement element during the shift is obtained.

  When the estimated temperature of the main frictional engagement element during the shift is determined, the control unit 10A as the thermal load determination unit 37A determines whether or not the estimated temperature is higher than the allowable temperature. It is determined whether or not the temperature of the main body side frictional engagement element is higher than the allowable temperature. When the estimated temperature is equal to or lower than the allowable temperature, the control unit 10A performs a shift using the post-restriction torque capacity of the main frictional engagement element as the pre-restriction torque capacity, as in the first embodiment. The transmission mechanism 6 is controlled as described above.

  On the other hand, when the obtained estimated temperature is higher than the allowable temperature, the control unit 10A obtains a temperature corresponding to the estimated temperature exceeding the allowable temperature. 1 Functions as the inverse calculation unit 42, and converts the temperature exceeding the limit (allowable temperature) into a calorific value. When the value of the heat generation amount that exceeds this limit is obtained, the control unit 10A then functions as the second inverse calculation unit 43 to convert the heat generation amount that exceeds the limit to the torque of the main frictional engagement element. Convert to capacity.

  When the torque capacity that exceeds the limit is obtained, the control unit 10A determines the post-limit torque capacity of the main frictional engagement element based on the torque capacity corresponding to the limit and the rotational speed difference before and after the shift. calculate. Further, the control unit 10 calculates the brake device shared torque capacity based on the torque capacity for the over limit, the torque capacity before the limit, and the torque sharing ratio of the main frictional engagement element.

  As described above, according to the present embodiment, in addition to the amount of heat generated in the main frictional engagement element at the time of shifting, the current temperature of the main frictional engagement element based on the accumulated heat balance before the shifting. An arithmetic operation is also performed, and an estimated temperature of the main frictional engagement element is calculated during the shift based on the heat generation amount and the current temperature. Then, the estimated temperature of the main body side frictional engagement element during the shift is determined in consideration of the current temperature of the main body side frictional engagement element at the start of the shift. It can be determined whether the combined element exceeds the allowable temperature.

<Third Embodiment>
Next, a vehicle control device according to a third embodiment of the present invention will be described. In the third embodiment, the post-restricted torque capacity and the brake device shared torque capacity are calculated using both the methods of the first and second embodiments. Therefore, the description of the same configuration as the first and second embodiments will be omitted in the following description.

  When the shift determination is performed based on the shift map, the control unit 10B performs both the method described in the first embodiment and the method described in the second embodiment in parallel, The post-restricted torque capacity and the brake device shared torque capacity are calculated by the method.

  Then, the post-restricted torque capacity calculated by these two methods and the brake device shared torque capacity are compared, and the value of the smaller post-restricted torque capacity and the larger brake device shared torque capacity is selected.

  That is, in the present embodiment, the control unit 10B determines whether the method of the first embodiment or the method of the second embodiment is performed by the main frictional engagement element during the shift. When it is determined that the temperature may exceed the allowable temperature, the result of determining that there is a possibility that the temperature may exceed the allowable temperature is employed. Also, in any method, when it is determined that the temperature of the main frictional engagement element may exceed the allowable temperature during the shift, the value on the side where the temperature of the main frictional engagement element during the shift becomes lower is adopted. doing.

  In the first to third embodiments described above, a hybrid drive device has been described as an example of a vehicle drive device. However, an engine is not necessarily required as a drive source, and a rotary electric machine is provided on the input side of the transmission mechanism. The present invention can be applied to any vehicle drive device including the above. Further, the speed change mechanism need not be a 6-speed multi-speed automatic speed change mechanism, and may be a speed change mechanism having 3 speeds or more.

  Further, the brake device 8 is not a simple disc brake device, but may be a side brake of a vehicle, for example, or may be a brake device for a wheel other than the driving wheel. In addition, the control units 10, 10 </ b> A, and 10 </ b> B are not necessarily configured by a single control device. For example, a plurality of control devices such as a control device that controls the vehicle drive device and a control device that controls the entire vehicle. It may be constituted by.

  In addition, it is not necessary for the speed change mechanism 6 to engage two friction engagement elements to form one shift stage. For example, three or more friction engagement elements can be engaged to A speed change mechanism that forms a gear position may be used. Also in this case, as described above, the post-restricted torque capacity and the brake device shared torque capacity of the main side frictional engagement element are set based on the heat generation amount of the main body side frictional engagement element at the time of gripping each frictional engagement element. Is done.

  In the second and third embodiments, the current temperature, the estimated temperature, and the allowable temperature are calculated in units of temperature. However, the current temperature, the estimated temperature, and the allowable temperature may be converted into units of heat generation using the heat capacity of the clutch. it can. Similarly, in the first embodiment, the calorific value and the calorific value limit value can be calculated in units such as temperature. That is, in the present invention, the terms such as calorific value and temperature may be expressed in any unit, and they are substantially the same.

  The amount of heat generated by the friction engagement element is obtained by subtracting the energy on the upstream side of the power transmission of the friction engagement element and the energy on the downstream side of the power transmission of the friction engagement element from the total energy in the power transmission system. While calculating as a calorific value, you may combine the invention described in embodiment mentioned above how.

3: rotating electric machine (motor), 6: transmission mechanism, 8: brake device, 10, 10A, 10B: control device (control unit), C-1 to C-3, B-1, B-2, F-1 : Frictional engagement element (clutch, brake), TR, TE: torque capacity of main frictional engagement element, _Tout : output torque

Claims (8)

When shifting the speed change mechanism in a regenerative state in which the rotating electrical machine provided on the input side of the speed change mechanism is regenerated, the state of the speed change mechanism is maintained while maintaining a state where the regenerative braking force of the rotating electrical machine can be transmitted to the wheels. A vehicle control device for controlling the speed change mechanism so as to change the friction engagement element.
A main gear that determines a target gear position when performing a shift of the speed change mechanism in the regenerative state and transmits the regenerative braking force while performing a slip rotation when a shift from the current gear speed to the target gear is executed. Determining whether the temperature of the side frictional engagement element is greater than the allowable temperature set according to each frictional engagement element;
When it is determined that the temperature of the main body side frictional engagement element is equal to or lower than the allowable temperature, the speed change mechanism is controlled to execute the speed change as it is,
When it is determined that the temperature of the main body side frictional engagement element is higher than the allowable temperature, the main body side during the slip rotation is performed so that the temperature of the main body side frictional engagement element is equal to or lower than the allowable temperature. A brake device for the wheel is set so that the torque capacity of the friction engagement element is set and a speed is changed while regenerating by the rotating electrical machine, and the fluctuation of the output torque transmitted to the wheel during the slip rotation is reduced. Actuate,
A control device for a vehicle. By calculating the amount of heat generated in the main frictional engagement element at the time of shifting, and determining whether or not the amount of generated heat is greater than the heat generation amount limit value set for each friction engaging element, Determining whether the temperature of the main frictional engagement element is greater than the allowable temperature;
The vehicle control device according to claim 1. Based on the cumulative heat balance before the shift, the current temperature of the main frictional engagement element is calculated, and the amount of heat generated in the main friction engagement element during the shift is calculated. Based on the current temperature of the combined element and the amount of heat generated in the main frictional engagement element at the time of shifting, an estimated temperature of the main frictional engagement element during the shift is obtained
It is determined whether or not the temperature of the main frictional engagement element during shifting is greater than the allowable temperature based on whether or not the estimated temperature of the main frictional engagement element during the shift is greater than the allowable temperature. To
The vehicle control device according to claim 1 or 2. In the case where the target shift stage is a shift stage separated from the current shift stage by a plurality of stages and the shift is performed by changing one friction engagement element forming the current shift stage, the gripping of the one friction engagement element is performed. When performing replacement, the friction engagement element that transmits the regenerative braking force while performing slip rotation is the main friction engagement element.
The vehicle control device according to any one of claims 1 to 3. In the case where the target shift stage is a shift stage that is a plurality of stages away from the current shift stage and the two friction engagement elements forming the current shift stage are changed, each of these two friction engagement elements is used. Each of the friction engagement elements that transmit the regenerative braking force while rotating the slip is used as the main frictional engagement element.
The vehicle control device according to any one of claims 1 to 4. Calculating the amount of heat generation based on the time required for shifting, the difference in rotational speed of the shifting mechanism before and after shifting and the torque capacity of the main frictional engagement element;
The vehicle control device according to claim 2 or 3. If it is determined that the temperature of the main frictional engagement element is greater than the allowable temperature, the torque shared by the wheel brake device is determined based on the torque capacity of the main frictional engagement element during the slip rotation. Set capacity, and actuate the wheel brake device based on the shared torque capacity;
The vehicle control device according to any one of claims 1 to 6. A speed change mechanism that has a plurality of friction engagement elements and forms a plurality of shift speeds by gripping the plurality of friction engagement elements;
A rotating electrical machine provided on the input side of the transmission mechanism;
A brake device provided on the wheel;
When shifting the speed change mechanism in a regenerative state in which the rotating electrical machine is regenerated, the friction engagement element of the speed change mechanism is replaced while maintaining a state where the regenerative braking force of the rotating electrical machine can be transmitted to the wheels. A control unit for controlling the transmission mechanism to perform
The control unit, when performing a shift of the transmission mechanism in the regenerative state, determines the torque capacity of the brake device that was in the non-braking state at the start of the shift according to the differential rotation before and after the shift and / or the required shift time. the varied during the shift to share the braking force in the gear shift, and said at shift end you said brake device and a non-braking state,
A vehicle characterized by that.

Images